Limited suction feed device



.lune 30, 1931. w. H. MUzzY v 1,812,014

LIMITED sUcTIoN FEED CDEVICE Filed sep. 21, 1929 zsneets-sheet 1 i Aazazvaqye.,

June 30, 1931. w. H. Muzzv 1,812,014

LIMITED SUCTIQN FEED DEVICE Filed sept. 21. 1929 2 sheets-sheet `2 4 a4/ 66 40 4 56 2f s 7 5 @AA/mm Cit Patented June 30, 193

i UNITED srarzes PA'iNT FFM@ -WILLIAI'I H. MUZZY, OF EVANSTON, ILLINOIS,ASSIGNOR 'IO PORTION, OF CHICAGO, ILLINOIS,

STEWART-WARNER Cone conronn'rion or VIRGINIA LIMITED SUCTION FEED DEVICEApplication filed September 21, 1929. Serial No. 394,152.

The purpose of this invention is to provide a construction for limitingto a predetermined degree the vacuum which Will be develcped in thevacuum chamber of a vacuum tan-k connected With a source of vacuum suchas the intake manifold of the engine served, in which the vacuum isliable lto be much greater than it is desirable to have developed in thevacuum tank. It consists in the elements and features of constructionshown and described'as indicated in the claims.

In the` drawings:

igure l is a vertical axial section of a vacuum tank constructedaccording to one form of this invention.

Figure 2 is a similar vievv of the second form of the invention.

Figure 3 isa similar view showing athirdV embodiment of the invention.

Figure 4 is a similar view showing a fourth form of the same genericinvention.

Tligure 5 is a diagrammatic view showing in elevation the vacuumtank'and ,the main fuel supply tank, the latter being broken anayforshowing Within the tank an arrangement of air and fuel floiv adapted toallow the vacuum tank to operate according to the principle of thisinvention and therefore' to embody said invention in a fifth form.

Referring in general to .all the forms of the invention shoe-,vn in theseveral figurest vri-l be understood that the vacuum tank is arranged tesupply fuel to the engine carbuaeter by gravity, the vacuum tank beingposit'ieneu at a suitable height abcve the level of the carhureter forthat purpose; thatthe vacuum tank is of the tivo-chamber type comprisingan upper chamber in which the vacuum is developed by` pipe connectionthereto from the intake manifold of the engine., and a reserve supplychamberlinto which the fuel is delivered by gravity from the vacuumchamber; that the vacuum chamber has pipe cennection by which it derivessupply of fuel from a main tank situated at the lower level, and fromWhich the fuel is lifted to the vacuum chamber by suction duek to therdegree of vacuum which is developed in the vacuum chamber., by itsVconnection with the engine intake manifold when an atmosphere inletport, with which the vacuum chamber is furnished at the top, is closedby the valve provided for that purpose, While the .communication .viththe intake mani-y fold is open; that the atmosphere inlet valve isoperated for opening by a float inthe vacuum chamber when the latterbecomes filled to a certain depth with fuel sucked up from tl e maintank; that the fuel is discharged into the lower chamber past a valvewhich is held closed by the suction While the vacuum chamber is beingfilled to a depth at whichV the float lifted by the risingk liquid opensthe atmosphere valve; vand when the atmospheric pressure thus admittedoffsets the vacuum due to the connection With the vengine intakemanifold, the liquid is discharged by gravity opening the outlet valveat the bottom of the vacuum chamber;

lt Will be understood further that in the l most common' form of vacuumtanks the opveration in this mannen-that is by the opening of anatmosahere Ivalve admitting air toy relieve the vacuum, is ensured byproviding a valve vvhich cuts off the suction at the same instant thatthe atmosphere valve is opened, so that the vacuum existing in the tank,and

by Which thefuel has been lifted to lill the i vacuum chamber toapredetermined depth, is prcmptly'neutralized by the inrush of air whenthe atmosphere valve opens. But if no valve is present to cut off thesuction, or if the valve provided for that purpose is poorly tted orWorn, or is kept from seating properlyv by dus-t particles, it Will belunderstood that-indien the engine vacuum is high the air may not'flovvin through the atmosphere valve rapidly enough to overcome the vacuum,because the air thus flowing in may be sucked out to the engine'intakemanifoldas fast as it can come in through an atmosphere inlet. rindifthis dii'licu'lty or defect is attempted to be metby making theatmosphere portso large that the-air inflow will offset eventhe maximumsuction due to intake manifold vacuum operating through the suctionpo-rt Without valvel orl unseated valve, -it may be seen that the forcencessaryto openv the atmosphere valvegagainst the suction When theengine intake vacuum is high Will require very large float, or, on theother hand, will necessitate making the suction port very small,resulting, in the first case, in requiringl the vacuum tank to be muchlarger than otherwise necessary and larger than desirable, and in thesecond case, in making the filling operation very slow, reducing thefuel supplying capacity of the tank of a given size.

rlf'he present invention in each of the forms illustrated obviates thesedefects of vacuum tanks of present common construction, by providingmeans preventing the vacuum developed in the vacuum chamber exceeding apredetermined degree, regardless of the high degree of vacuum derivablefrom the intake manifold.

Referring to the construction shown in Figure 3 which shows the simplestform of the invention z-The vacuum tank comprises a vacuum chamber, A,and a reserve supply chamber, B. A vertical tube, 20, of small diameteris provided extending up int-o the vacuum chamber, A, and down into thereserve supply chamber, B. rlhis pipeat its top in the vacuum chamber,A, is provided with a weighted valve, 2l, having a guiding stem, 22, andarranged tonormally close the upper end of the tube, 20, the lowei` endof which is open in the fuel reserve chamber as mentioned and as seen at23.

A cork fioat, 25, is mounted on a stem, 26, which carries at its upperend an atmosphere inlet controlling valve, 27, seated on a valve :iseat, 28, formed inthe top, 29, of the vacuum tank. The lower end of thestem, 26, is guided in a pipe, 30, which constitutes the dr in outlet ofthe vacuum chamber by which the fuel is discharged into the reservesupply chamber, B, past the customary flapper valve, 3l.

rlhe reserve supply chamber, B, is provided with a stand pipe, 82, whichcommunicates with the outlet, 33, fro-m which pipe connect-ion indicatedat 33 leads to the carbureter.

A fitting, 34, connected at the top of the vacuum tank affordsconnection for the suction pipe indicated at 35 arranged to lead to theengine intake manifold. rlhe suction port at which the fitting, 35, isconnected is very small as seen at 36 being preferably of about the sizeof a #72 drill. A fitting, 37, affords connection with the top of thevacuum tank for the fuel supply pipe indicate-d at 37a and which may beunderstood as leading from the main supply tank at the rear of thevehicle.

The atmosphere inlet port, 28, furnished with the atmosphere valve, 27,is guarded by a casing, 40, having a goose-neck breather pipe, Lil, ofusual construction.

The purpose of the stand pipe, 32, is to ensure that a certain amount offuel will always be trapped in the lower part of the reserve supplychamber, B, thus guarding against any liability of this amount ofgasoline being drained off even though the tank is otherwise completelydrained and exhausted of supply available for the carbureter.

'The operation of the structure will be understood from the foregoingdescription, but may be further indicated. Assuming the vacuum tank tobe primed,-that is initially supplied with fuel occupying the lowerreserve supply chamber, B, and standing in the vacuum chamber at the lowlevel .at which the atmosphere inlet valve is held closed by' the weightof the ioat,-When the vacuum developed in the vacuum chamber byconnection with the intake manifold reaches a suliicient degree,gasoline is drawn from the main tank .at the rear of the machine throughthe pipe connection, 37.

And when the vacuum is sufficient to lift the weighted valve, 2l,gasoline also passes up in the pipe, 20. As the inflow to the vacuumtank due to the engine suction and resulting vacuum in the vacuumchamber raises the level in the vacuum chamber, when the liquid reachesa predetermined height in the vacuum chamber, `the float will open theatmosphere valve, which, however, is dimensioned for being thus openedonly against a predetermined vacuum, desirably not exceeding five inchesHg. 1n the ordinary operation the valve, 2l, remains closed up to avacuum of about three or four inches Hg.

. and the full force up to this degree is utilized for lifting the fuelfrom the rear tank. But when the vacuum in the chamber, A, exceeds threeor four inches, Hg. the valve, 21, opens and is carried up on a columnof gasoline which is sucked up in the pipe, 20. The gasoline thus entersthe chamber, A, with sufficient rapidity to prevent the vacuum in thatchamber exceeding five inches Hg. and to cause only a limited amount ofair to pass the small suction aperture, 36. The relation between theweight of the valve, 21, and the size of the aperture, 36, determinesthe degree of vacuum which will be developed and maintained in thevacuum chamber, A.

Upon relief of the vacuum of this limited degree which is effected bythe opening of the .atmosphere valve, by the rising of the float, thefuel is discharged by gravity to the reserve supply chamber, B, passingthe lapper valve, 3l, according to the usual operation of vacuum tanksof this type.

Referring to the form shown in Figure 2 z-In this embodiment of theinvention, the vacuum relief is aorded by admitting air directly fromthe atmosphere, instead of admitting the liquid from the lower chamberunder atmospheric pressure. For this purpose there is provided at thetop of the vacuum chamber a vacuum relief or atmosphere vent port, inaddition to the atmosphere inlet reiger-i which is controlled bythefloat-operated valve. This relief port is provided in a fitting, 50,inserted in the cap, 29, of the vacuum chamber, .an-d having forcontrolling it a valve, 51, having a long tapering shank, as

seen at 52, and terminating in a threaded stem, 53, for receiving anadjustable stop nut, 54, a spring, 55, being coiled about the stem andreacting between the stop nut and shoulder, 56, formed in the fitting,50, by

the description of the operation of the first described form withouscription.

Referring to the embodiment of the invention shown in Figure 4 y In thisembodiment the vacuum is relieved by the admission of both atmosphericair and liquid drawn from the reserve supply chamber. In this form theoperation of the float and other parts is the same as above describecfurther specific de- `'in respect to the form iirst above described.

In this form there is provided a. loop pipe, 60, having its bend at thelower part of the reserve supply chamber and having one limb, 61,extending (liquid iight) through the bottom of the vacuum chamber, A,and the other limb, .62, extending outside the vacuum chamber in theannular space, B1, around the same within the reserve supply chamber, B,both limbs of the U-pipe are open at the upper end, the first mentionedlimb thus being open to the pressure existing in the vacuum cham.-

ber and the other limb being open to an ati-- mospheric pressure whichis always operative a in the reserve supply chamber which it will beunderstood has the yatmosphere inlet at the upper end as soon at 19.

VThe loop pipe, .60, has at its lower end an aperture, 63, by whichliquid is admitted from the reserve supply chamber, B, and drawn upwardin the limb, 61, mixed with air which is at the saine time drawn -downfrom'the limb, A62, and passing around the bend men-` tioned with theliquid moving upward in the limb, 61'.

ing the trapping of liquid inthe lower part of the. reserve supplychamber, B, and thus ensures that the liquid will 'oe always drawn inthrough the port, 63, the friction of which in the pipe will operatewith the effect for restricting entrance of liquid and air, which is thefunction of the. weighted valve in the form shown in Figure 3, and ofthe-spring, 55, in the form shown in Figure 2. And it may be understoodthat the form and dimensions The stand pipe., 32, operates 'as inthepreviously described form, for ensurof this loop pipe, particularly asto diameter, will be determinedexperimentally for limiting the vacuum inthe vacuum chamber to the predetermined degree. And it will beunderstood that the weighted valve may be applied at the discharge ofthe limb, 61, as in the form of Figure. 3, to supplement the restraintof flow obtained from friction in the pipe.

The operation of 'this form may be readily understood from the foregoingdescription thereof and of the description of the operation of thepreviously described form.

Referring to the form shown in Figure 1 In this embodiment of theinvention the operf ation is identical in principle and very similar indetail to that shown in Figures 2, 3 and 4 above described, thedifference consisting in that auxiliary structure for controlling thevacuum is located Within the vacuum chamber. Y

Said auxiliary structure comprises what might be regarded as a miniaturevacuum tank, having a chamber which is in communication with the vacuumchamber, and experiences the same degree of vacuum, and a lower chamberwhich is at all times under atmospheric pressure, 'and into which theliquid content of the first mentioned upper chamber is delivered bygravity when the atmosphere inlet is opened by the float, said floatbeing located in the upper chamber of the auxiliary device and the valvewhich it controls being a "ranged to admit atmosphere not only to saidauxiliary device but also to the main vacuum chamber of the vacuumtank.' 1^

Referring to the structure in detail :HThe auxiliary structurec-omprisesa. Vcup-shaped sheet metal stamping, 80, open at its upper endand flanged for securing itat that end to the under side of the cap, 29,of the vacuum tank, the cavity of said cup memberA being partitionedas'seen at 81 fo 1ming an upper vacuum chamber, 82, and a lower chamber,83. The member, 80, has at its upper part a plurality of apertures, 84,aifording free communication between the upper chamber,

.82, and the vacuum chamber, A, of the vacuum tank. A pipe, 85, openfrom end to end, eX- tends from the partition, 81, up through thechamber, 82, and through the cap, 29, into the chamber, 40, with whichthe goose-neck breather pipe, 41, is connected for admitting atmosphereto the atmosphere inlet port, 38, and the atmosphere controlling valve,39, has

its stem, 26X, extending down in the chamy iii-i in the lower chamber,83, to nearly the bottom thereof, is open at both ends, therebyaffording free flow communication between the two chambers, 81 and 82. Apipe, 88, mounted in the partition, 81, extends up in the chamber, 82,to about the level of the apertures, 84, and extends down in thechamber, 8l, to the saine level as the pipe, 87, said pipe, 88, being`open at both ends thereby affording comn'iunicati-on to the lower partof the lower chamber and to the upper part of the upper chamber, 82.

The operation of this construct-ion may be understood from thefore-goin@ description but may be further descril ed The apparatus beingprimed, that is, having the lower chamber occupied with liquid extendingup in the annular space, B1, between the two chambers, A and B, to thelow level, that is the level to which the liquid falls when discharginginto the lower chamber when the atmosphere inlet is open ,-enginesuction operating for developing vacuum produces vacuumy in the vacuumchamber, A, and in and to the same degree the chamber, 82, of theauxiliary structure causing the inflow ofr liquid entering the vacuumchamber rising therein to the level of the port, 89, enters the chamber,82, of the auxiliary structure and flows therefrom by way of the pipe,87, into the lower chamber, 8l, of the auxiliary structure causing thatchamber to be filled sealing the lower end entrance to the pipe, 88,through which the liquid is sucked up by reason of the vacuum in the.chamber, 82, and discharged from the upper end of pipe, 88, accumulatingin the chamber, 82, to the level to which at the saine time itaccumulates in the main vacuum chamber, A.

The liquid thus acciunulating in the chamber, 89 causes the float belifted and to open the atmosphere valve, which the discharge of theliquid contents of the vacuum cl into the reserve suppl v same time the,d

charge her, 82, chamber,

will be une l which wil: bdc in the main vacuiu itcd l y the i c c invacuum cl amber, A. wil lle understood that the pi s mentioned wi" bedimensioned bv e.A lnent for rende i nce te the L flew such te, overcomeby vacuum of tlic predeterm degree de feioped in the vacuum chambers,and A. lt wil be understood also that the return iow of the liquid fromthe chamber, 82, to the chamber, 81, when the 'atmosphere valve is open,ensures the presence at all times in the chamber, 8l, of the necessaryquantity of liquid to operate for sealing the lower end of the pipe, 88,and 'supplying that pipe completely with liquid in the upward flow fordischarge in the chamber, 82, for relieving the vacuum. l

Referring to the construction indicated in Figure liz-lt may beunderstood that the construction of vacuum tank, V, is substantially thesame as that shown in thc previously described figures in respect to thevacuum chamber, reserve supply chamber, fuel supply connection (by thepipe, 90), valveless suction connection, atmosphere inlet with valvecontrol by float in the vacuum chamber, and bottom outlet from thevacuum chamber to the reserve supply chamber with valve seated by thesuction and opened by gravity discharge of the liquid when the vacuum isrelieved by the opening of the atmosphere valve by the float.

in this form the relief of vacuum is afforded by ineansof pipe, 91, inthe main fuel supply tank open for free access of atmosphere at itsupper end, and connected at the lower end into the fuel intake pipe, Q3,near the lower end intake thereof as indicated at 94.

lt will be recognized upon careful consideration 'that whatever thedegree of vacuum derivable in the vacuum chamber of the vacuum tank fromthe engine intake manifold,`

the vacuum actually resulting in the chamber will be measured by-or bethe measure cf the resistance of the liquid column eX- tending from theliquid level of the main supply tanl: to the level of fuel discharge inthe vacuum tank; and that this resistance consists of the hycirostaticvalue of the liquid column per se plus the resistance to movement of theliquid in the conduit due to friction and viscosity of the liquid andrestriction of access of liquid to the pipe.

It will be recognized that with the pipe large'enough to render thefrictional resistance negligible, the vacuum in the vacuum chamber wouldbe at all times measured by the hydrostatic value of the liquid columnin the supply pipe. With the intake to the fuel supply pipe in the mainsupply tank sealed by the liquid therein, an excess of vacuum in thevacuum chamber to over predetermined degree less than the vacuumtheoretically derivable from the intake manifold, will be due torestriction of access of liquid to the supply line, or to otherresistance to flow therein. Upon consideration it may be recognized thatthe provision afforded by the air inlet pipe, 91, for access of air tothe liquid column in the pipe line 93, 90, will cause said liquid columnto be aerated and thereby reduced in density and weight, andcorrespondingly reduced in hydrostatic Value; and at the same time therewill be reduction in the frictional iso resistance to flow toward thevacuum tank;

'and that the delivery of the air with the liquid into the vacuumchamber will have the same effect to relieve the vacuum as the admissionof air in any other manner or by any other course. Y

The dimension of the, air pipe, 91, and of its port of communicationwith the fuel supply pipe will be determined experimentally to limit thevacuum in the vacuum. chamber to the predetermined degree.

I claim:

l. In liquid feeding system in whichl quid is lifted from a low levelsupply to 'a-chamber at a higher level by the creation of a partialvacuum in said chamber and in which means is provided for periodicallyreleasing the elevated 1liquid for discharge by gravity, said meansincluding an atmosphere valve to vent the chamber, and a floatYconnected for opening said valve upon accumulation of liquid in thechamber; means to prevent an excessive degree of vacuum in the chamber,comprising a supplemental passage for supplying additional fluid theretoagainst resistance to the movement of such fluid iiow, the resistance ofsaid passage bei-ng adapted tobe overcome by thev suction when thevacnum in the chamber exceeds a predetermined value; a supplementalchamber within the vacuum chamber having an inlet for liquid disposedbelow the lower limit of movement of the fioat and a transfer passageextending fiom the lower portion of said supplemental chamber to a pointabove the normal maximum liquid level in the vacuum chamber, saidsupplemental chamber being constantly open to the atmosphere, wherebyexcessive vacuum tends to transfer liquid from said supplemental chamberto the vacuum chamber for 'satisfying the excess of vacuum.

2. In a liquid feeding system in which liquid is lifted from a low levelsupply to 'a chamber at a higher level by the creation of a partialvacuum in said chamber and in which means is provided for periodicallyreleasing the elevated liquid forV discharge by gravity, said meansincluding an atinosphere valve to vent the ch amber, and a floatconnected for opening said valve upon accumulation of liquid in thechamber, means to prevent an excessive degree of vacuum in the chamber,comprising a supplemental passage for supplying additional iiuid theretoagainst resistance to the movement of such fluid liow, said passageadapted to be overcome by the suction when the vacuum in the chamberexceeds a predetermined value, a

supplemental chamber within the vacuum chamber having an inlet forliquid disposed below the lower limit of movement of the float andtransfer passage extending from the lower portion of said supplementalchamber to a point above the normal maximum liquid level in the vacuumchamber, said sup-l plemental chamber being constantly open to theatmosphere, whereby excessive vacuum tends to transfer liquid from saidsupplemental chamber to the vacuum chamber for satisfying the excess lofvacuum, said float beinO' surrounded by an enclosing cup within into thevacuum chamber. 4. in the combination defined in'claim 2,

said cup being provided with an overiiow port in its upper portion toprevent floodingof the liquid through the atmosphere vent.V

5. ln a liquid feeding system in which liquid is lifted from a low levelsupply to a chamber at a higher level by the creation of a partialvacuum in said chamber and in which means is provided for periodi allyreleasing the elevated liquid for discharge by gravity, said meansincluding' an atmosphere valve to vent the chamber, and a floatconnected for opening said valve upon accumulation of liquid in thechamber, means to prevent an excessive degree of vacuum in the chamber,comprising a supplemental passage for supplying additional iiuid theretoagainst resistance to the movement of su-ch l fluid flow, the resistanceof said passage being adapted to be overcome by the suction when thevacuum in the chamber exceeds a predetermined value; a supplementalAchamber within the vacuumr chamber having an inlet for liquid disposedbelow the lower limit of movement of the float, and a transfer passageextending from the lower por tionof said supplemental chamber to'a pointabove the" normal maximum liquid level in the vacuum chamber, saidsupplemental chamber having` a constantly open atmosphere vent', wherebyexcessive vacuum tends to transfer iquid from said supplemental chamberto the vac uum chamber for satisfying the excess of vacuum, theatmosphere vent for the supplemental Vchamber being a tube which passesthrough a clearance opening in the lioat and eoV the transfer passagebeinga tube which exy tendssimilariy through aclearance opening in thefloat, whereby said Atube serves to guide the float in its movement.

6. in a liquid feeding` system in which gravity, said means including anatmosphere tion of li d in the chamber; means to prevent en .ncessivede=--ee of vacuum 1n the chamber, comprising a supplemental passage forupplying additional fluid 'thereto against resistance to the movement ofsuch fluid flow, the resistance said passage being adapted ome by thesuction when the vacuum intne chamber exceeds a predetermineir value,said loiv level` supply comprising a tank with a liquid supply tubeleading upwardly from the bottom portion 'l .ereof to the vacuumchamber, the upper portion of said supply tank being subject toatmospheric pressure, and the means to prevent excessive vacuumComprising a branch tube opening in the upper portion of the supply tankand connected into the supply tube at a point near the bottom of thetank, whereby excessive vacuum in the chamber will dranv air through thebranch tube and through the supply tube to satisfy the excess of vacuumin the chamber.

Q7. in liquid reedn r in which liquid is lifted from a lov: level supplyto a ciiamber at a higher level by the crea-tion of a partial vacuum insaid chamber and in which means is provided for periodically rclcasingthe elevated liquid for discharge by gravity, said means including anatmosphere valve to vent the chamber, and a float connected for openingsaid valve upon accumulation of liquid in the chamber; means to preventan excessive degree of vacuum in the chamber, comprising a supplementalpassage for su pplying addi-tional fluid thereto against resistance tothe movement of such iuid flow, the resistance of said passage being`adapted to be overcome by the suction when the vacuum in the chamberexceeds a predetermined value, a reservo': communicating with thechamber to receive the liquid discharged by gravity therefrom, saidreservoir being open to atmospheric pressure, and a passage connectingsaid reservoir with the upper portion of the chamber having outlet inthe upper part of the chamber and inlet in the lower part of thereservoir, with a valve yieldingly seated with predetermined forcecontrolling said outlet, whereby it is adapted to be opened by vacuum inthe chamber exceeding said predetermined force, for admitting liquidfrom the reservoir to the chamber to satisfy such excess of vacuum.

Q ln a liquid feeding system in which i. liqu: l is lifted from a lowlevel supply to a chamber at a higher level by the creation of a partialvacuum in said chamber and in which means provided for periodicallyreleasing the elevated liquid for discharge by gravity, said meansincluding an atmosphere valve to the chamber, and a float connected foropening said valve upon accumulation of liquid in the chamber; means toprevent an excessive degree of vacuum in the chamber, comprising asupplemental passage Vfor supplying additional fluid thereto againstresistance to the movement of such fluid flow, the resistance of saidpassage being adapted to be overcome by the suction When the vacuum inthe chamber exceeds a predetermined value, a reservoir communicatingWith said chamber to receive the liquid discharged by gravity therefrom,said reservoir being open to atmospheric pressure at the upper part, apassage connecting said reservoir with the chamber having outlet at theupper part of the chamber and inlet at the lower part of the reservoir,a yieldingly seated valve controlling said outlet adapted to be openedby vacnum exceeding the force by which the valve is held yieldinglyseated, for admitting liquid from the reservoir to satisfy such excessvacuum in the chamber, the reservoir having its discharge outlet at asubstantially higher level than the inlet to said passage, wherebyliquid is trapped in the reservoir for delivery through said passage tothe chamber for satis fying the excess vacuum therein.

In testimony whereof, I have hereunto setmy hand this 16th day ofSeptember, 1929.

VILLIAM H. MUZZY.

vso

